Faruq Mohammad; Hamad A. Al-Lohedan; Hafiz N. Al-Haque
Abstract
Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic ...
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Hybrid materials based on metals and natural polymers are a promising class of nanocomposites; there is an increasing interest in metal nanoparticles (NPs) due to some fascinating characteristics associated with their nanosizes such as optical, conducting, catalytic, mechanical, sensing and superparamagnetic properties. Despite these favorable properties, the natural tendency of NPs for aggregation, high reactivity due to surface charges, and high rate of toxicity are limiting their applicability in biomedical sector. Chitosan, a naturally available amino polysaccharide biopolymer obtained from the exoskeleton of crustaceans (crabs and shrimp) and cell walls of fungi, displays unique polycationic, porous, chelating, bioadhesive and film-forming properties. The in-built characteristics of chitosan biopolymer can be utilized to alter the negative shades of metal NPs, thereby enhancing the applications in many different areas. The incorporation of chitosan significantly affects the steric stabilization of metal colloids, creates extra functional groups for biomolecule conjugation, renders the NPs suitable for bio-markers, protects metal ions from further oxidation/reduction by means of polymer coordination and has a control over toxicity. Thus by taking advantage of the additional features offered by the combination of chitosan and metal NPs, this report is designed to provide an overview about the metal NPs type, synthesis and applications in bioengineering and biomedical sector. Starting with the influencing properties due to their combination, we further reviewed the literature related to chitosan and metal NPs applicable for medicine with a specific focus on cancer diagnosis and treatment, advanced drug delivery, tissue engineering and surgical aids, to mention some.
Tanvir Arfin; Faruq Mohammad
Abstract
In the present study, a very prominent cost effective sol-gel method was used to amalgate the ethyl cellulose-tin(II) hydrogen phosphate (EC-SnHPO4), an organic–inorganic composite material with certain acidic condition practiced in a conductivity system. The physical characterization of the material ...
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In the present study, a very prominent cost effective sol-gel method was used to amalgate the ethyl cellulose-tin(II) hydrogen phosphate (EC-SnHPO4), an organic–inorganic composite material with certain acidic condition practiced in a conductivity system. The physical characterization of the material was described by the UV-Vis and FTIR study. The different monovalent electrolytes such as KCl (aq) and NaCl (aq) at diverse temperature range was employed to measure the conductivity of EC-SnHPO4 and also for the concentration to explore between affinity of conductivity and electrochemical properties of the material. From the study, the conductivity was established to be less for K + than Na + . For such process in addition, the different parameters such as ionization potential, oscillator strength, transition dipole moment, resonance energy, and transition energy were investigated. Finally, the anticancer effect against the MCF-7 breast cancer cell line and the antibacterial activity against two different bacterial strains show the potential pharmacological activity of the EC-SnHPO4 towards medical applications.
Faruq Mohammad; Tanvir Arfin
Abstract
In continuation to our previous work, the superparamagnetic Fe3O4@Au core-shell type nanoparticles (NPs) were further characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), electrical conductivity, impedance and cyclic voltammetry measurements. From the analysis of ...
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In continuation to our previous work, the superparamagnetic Fe3O4@Au core-shell type nanoparticles (NPs) were further characterized by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), electrical conductivity, impedance and cyclic voltammetry measurements. From the analysis of DSC and TGA results with our Fe3O4@Au NPs of about 6.25 ± 0.6 nm size, we observed a clear endothermic peak at 310°C due to the decomposition of the oleic acid/oleylamine surface ligands and the particles found to contain more than 80% of the metallic content from the mixed compositions of gold and iron oxide were observed. Because of the conduction through the Fe3O4@Au grain, the impedance profile of the pellet exhibited a well-resolved semi-circle and an inclined spike in a far low-frequency region. The electrical conductivity of the Fe3O4@Au material found to be increased with an increase of temperature. The standard Gibbs free energy (ΔG) of the reaction provided a criterion for spontaneous changes in the equilibrium of the material. From the analysis of the results of ΔG, it appears that at 25°C temperature, ΔS found to be negative. The calculated enthalpy, ΔH = -0.635 kJ/mol, at the corresponding entropy of ΔS = -0.132 kJ/mol. Finally, the activation energy in temperature range of 25-200°C for the Fe3O4@Au core-shell material was calculated using Line fitting and the surface characterization by using cyclic voltammetry. The electrochemical redox property of the Fe3O4@Au shows quasi-reversible wave corresponding to Au 3+ /Au 2+ .In addition, the electrochemical parameters for Fe3O4@Au NPs of E c p < /sub>, E a p < /sub>, E o 1/2 and were also obtained. Since the Fe3O4@Au material has low activation energy at low temperature range which makes it a good candidate as an ion conductor and even has the potential uses in many solid state devices and also in the future prospects of electrochemistry applications.